Chaffee Transmission Questions

[Malcolm Towrie]

Hi, I got one of the GM Hydramatic transmissions off a M24 Chaffee apart and I have some questions:
- the tranny oil cooler has large ballooned spots in the cooler plates shown below. The cooler is on the suction side of the oil pumps so sees very low pressure, going on below atmospheric. Anyone any idea why has this happened?

- the front clutch pack is smoked including the aluminum apply piston. One of the return springs punched a hole through it. Who sells hard parts like this for these old trannies?

- who has Chaffees who could answer questions on these trannies?

Thanks,
Malcolm

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[Bob Phillips]

why dont you compare a chaffee tranny parts book against a G749 hydramatic transmission book and see if there are common parts in both transmissions. If so call Brian Asbury who may still have some old rebuilt G749 transmissions available to strip for parts. Just a thought.

[Malcolm Towrie]

Thanks, Bob. My problem is I don't have a parts manual for the tranny. Also, I can tell from the photos and info in my 1945 Chaffee tranny manual that I don't have an original tranny. I assume it's a later model. And I'm finding that GM tweaked their newly-designed hydramatic every year, so by the time they were being installed in the deuces, there were a lot of differences.

Anyway, I got lucky. The damaged apply piston has the part number cast into the aluminum and I found a NOS one on eBay for reasonable money!

Rebuild gasket and seal kits and clutch plates are still available so I should be ok now, although the blistered cooler worries me. I'll just have to pressure test It (gently) and reuse it.

Fingers crossed the other tranny, which is also acting up, doesn't need any hard parts.

Malcolm

[Frank v R]

try calling Bob Rubino in NJ tell him I told you to call, Milspec Restoration
908-475-2799 he may be able to shed some light on the cooler , and if you need parts try calling Brent Mullins jeep parts, he does a lot of Armour and has lots of NOS parts
regards Frank

[Bob Phillips]

i used to have a couple of used transmissions for the Chaffee and I think they were shorter than most hydramatic transmissions and had no reverse gear, the reverse being in the transfer case. would a later transmission still work in a \chaffee or is this a non Chafee application?

[Bob Phillips]

So I just checked my G749 ord 9 and the oil cooler for the G749 which appears identical to the picture posted is identifed as G200-5608479 cooler assy, oil
This means it is the same in both applications. Used G749 transmissions are still widely available in Ontario junkyards, no need to go far. If you can't find one pm me for more leads.